I think it’s normal.
I made a similar move a few years ago, from 10+ years at the old job. There were red flags that came up a couple months in, but I decided to stick it out.
It took me over a year to really feel like it was the right decision. But the red flags faded as it turned out there were just some growing pains going on. Leadership managed to resolve the major issues and I’ve turned out to be pretty happy in the new position.
I’m not saying the same will be true for you… Some red flags signal issues that are correctable, but others signal toxicity or other things that are unlikely to be fixed.
But IMHO, 3 weeks seems like a short time unless the issues are really egregious.
Also consider that if you go back to your old job, your old boss may treat you worse than previously.
If you don’t like the new job and don’t want to give it more time, consider starting to look for something new immediately (you were headhunted, so your skills are obviously desirable) and continuing to move forward rather than going back.
My 2c.
What works for me:
Have radar coverage to keep an eye on biter expansion
Keep an eye on your pollution cloud, and reduce production (at least initially) if it’s expanding too fast.
Build up military tech alongside your other tech
Pending 3, take out biter nests that expand too close to the edge of your pollution cloud.
If you can do 1-4, biters should never actually get to your base.
Then by the time you’re ready to go off world, make sure you have a perimeter lined with turrets (and some walls to help protect the turrets), repair bots and repair kits, automated ammo production, and supply lines (belts or trains) to automatically get that ammo to your perimeter turrets.